diff --git a/Controller/ThreadController.php b/Controller/ThreadController.php
index 9abc5ac49..14c6bbd1e 100644
--- a/Controller/ThreadController.php
+++ b/Controller/ThreadController.php
@@ -21,6 +21,7 @@
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\Validator\Validator\ValidatorInterface;
 
 
 define('HTTP_BAD_REQUEST', 400);